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Estimating Wind Speeds in Tornadoes and other Windstorms: Development of an ASCE Standard



Frank Lombardo, Tanya Brown, Marc Levitan, James LaDue


Estimation of near-surface wind fields in tornadoes has important applications in both structural engineering and meteorology. Estimated near-surface wind speeds are used in the design of nuclear power plants, safe rooms, storm shelters, and could be used in tornado-resistant design for other buildings and residential structures. A better understanding of the near-surface wind field is important for understanding possible changes in the tornado record due to climate change and for assessing likelihood and intensity of tornadoes given certain atmospheric conditions. However, assessing the near-surface wind speeds in tornadoes is difficult due to complex flow in time and space, and it is difficult to obtain in-situ measurements. Radar measurements have provided great insight into tornadic wind flow, however they typically cannot sample the near-surface. Because of these difficulties, meteorologists and engineers have turned to damage-based methods to estimate near-surface wind speeds in tornadoes such as the Fujita (F) Scale and the subsequent Enhanced Fujita (EF) Scale. However, damage-based estimates of near-surface wind speeds have not been validated and their accuracy has been questioned, spurring other methods to reconstruct near-surface tornado wind fields such as assessing tree fall patterns. This paper will discuss background on near-surface wind speed estimation methods (e.g., in-situ, radar, damage-based) and the state of the science with regards to these methods. To standardize these methods, a process is currently underway through the American Society of Civil Engineers (ASCE) to develop a standard for wind speed estimation in tornadoes and other windstorms. This standard will be supported by the development of sub-committees in different wind speed estimation methods as well as a main committee to provide overall support. The initiation, development and current status of the standard will be also discussed in the paper.
Proceedings Title
Proceedings, 14th International Conference on Wind Engineering
Conference Dates
June 21-26, 2015
Conference Location
Porto Alegre, BR


Tornado, Windstorm, EF-Scale, ASCE, Standard, Wind Speed, Wind Speed Estimation, Wind Damage


Lombardo, F. , Brown, T. , Levitan, M. and LaDue, J. (2015), Estimating Wind Speeds in Tornadoes and other Windstorms: Development of an ASCE Standard, Proceedings, 14th International Conference on Wind Engineering, Porto Alegre, BR (Accessed April 21, 2024)
Created June 21, 2015, Updated July 14, 2022